JAXB XML 输出格式问题 [英] JAXB XML output format questions

问题描述

我有具有以下结构的 Java 类(类名不暗示任何内容，我只是编造了它们).

I have Java classes with the following structure (the class names do not imply anything, I was just making them up).

package test;

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlValue;

@XmlRootElement
public class Test
{
    @XmlAccessorType(XmlAccessType.FIELD)
    static class Machine
    {
        @XmlElementWrapper(name="servers")
        @XmlElement(name="server")
        List<Server> servers = new ArrayList<Server>();
    }

    @XmlAccessorType(XmlAccessType.FIELD)
    static class Server
    {
        Threshold t = new Threshold();
    }

    @XmlAccessorType(XmlAccessType.FIELD)
    static class Threshold
    {
        RateThreshold load = new RateThreshold();
    }

    @XmlAccessorType(XmlAccessType.FIELD)
    static class RateThreshold
    {
        @XmlAccessorType(XmlAccessType.FIELD)
        static class Rate
        {
            int count;
            Period period = new Period();
        }

        @XmlAccessorType(XmlAccessType.FIELD)
        private static class Period
        {
            @XmlAttribute
            private String type = "second";

            @XmlValue
            private float period;
        }

        Rate min = new Rate();
        Rate max = new Rate();
    }

    @XmlElementWrapper(name="machines")
    @XmlElement(name="machine")
    List<Machine> machines = new ArrayList<Machine>();

    public static void main(String[] args)
    {
        Machine m = new Machine();
        Server s = new Server();
        s.t.load.max.count = 10;
        s.t.load.min.count = 1;
        m.servers.add(s);

        Test t = new Test();
        t.machines.add(m);

        JAXBContext jaxbContext;
        Marshaller marshaller;
        try
        {
            jaxbContext = JAXBContext.newInstance(Test.class);
            marshaller = jaxbContext.createMarshaller();
            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
            marshaller.marshal(t, System.out);
        }
        catch (JAXBException e)
        {
            e.printStackTrace();
        }
    }
}

我遇到的问题是在编组 Test 实例时 JAXB 生成的 XML 输出.XML 输出将始终如下所示:

The problem I am having is with the XML output generated by JAXB when marshalling a Test instance. The XML output would always look like the following:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<test>
    <machines>
        <machine>
            <servers>
                <server>
                    <t>
                        <load>
                            <min>
<count>1</count>
<period type="second">0.0</period>
                            </min>
                            <max>
<count>10</count>
<period type="second">0.0</period>
                            </max>
                        </load>
                    </t>
                </server>
            </servers>
        </machine>
    </machines>
</test>

如您所见，某些元素没有正确缩进(即最深的元素、计数和句点).这是为什么?我创建 JAXB 上下文的方式有问题吗?或者 JAXB 可以递归缩进多少个元素有最大限制?我怎么能解决这个问题?请注意，我也将 JAXB_FORMATTED_OUTPUT 设置为 true，但仍然得到不正确的缩进.

As you can see, some elements are not being indented properly (that is, the deepest elements, count and period). Why is that? Is there something wrong with the way I created the JAXB context? Or is there a maximum limit to how many elements that can be indented recursively by JAXB? How could I fix this? Note that I have also set JAXB_FORMATTED_OUTPUT to true, but still get the improper indentation.

谢谢.

推荐答案

缩进发生模 8，在

com.sun.xml.bind.v2.runtime.output.IndentingUTF8XmlOutput

你发现

int i = depth%8;

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